This invention relates to wire drawing dies.
Wire drawing dies consisting of a diamond compact core held in a suitable support are extensively used in industry. The hole through which the wire is drawn is provided axially through the diamond compact core. The support will generally either be a steel or cemented carbide ring.
One method of making these wire drawing dies includes the steps of providing the diamond compact core, providing the support which has a hole extending therethrough, the cross-section of which is slightly smaller than that of the core, heating the support to cause it to expand, sliding the core into the hole, and allowing the support to cool and contract around and on the core. This produces a wire drawing die blank. The wire drawing die is produced from this blank by forming a suitable hole axially through the diamond compact core. The wire drawing die is then mounted in a larger support ring, for use. It is mounted in this larger support ring by brazing the steel or cemented carbide support to the larger ring. In so doing, the support is heated and expands and dislodgment of the core in the support can occur. When there is such dislodgment, the core will no longer lie true in the hole through the support.
An example of a wire drawing die utilising a diamond compact core is described in U.S. Pat. No. 3,831,428.